Sandpapering-machine.



2 SHEETS-SHEET l.

PATENTED JUNE 2, 1908.

SANDPAPERING IVIICHIEE.-

APPLIOATIOH Hum AUG. 29, 1907.

| llflllll.

s Till@ PATENTED JUNE 2, 1908.

J. P. SIMMONS. SANDPAPERING MACHINE.

APPLICATION FILED AUG. 29, 19 07.

2 SHEETS-SHEET 2 ATTORNEY .papermg machines,

' novel sauras earner, ernten.

JOHN P. SIMMONS,` OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO HARRON,RICKARD &

MCCONE, OF SAN FRANCISCO, CALIFORNIA, A

CORPORATION OF CALIFORNIA.

sAnDPaPnnme-Macnrnn.

no. esatte.

To all whom it may concern:

Be it knownA that I, JOHN P. SIMMONS, a citizen of the United States,city' and county of San Francisco and State of California, have inventedcertain new and useful Improvements in Sandpapering-Machines, oi whichthe following is a specification.

My invention relates to the class of sandand particularly to A.animprovement in the drums thereof which carry the sand-paper, saidimprovement having for its object the provision of a simple and eHectivemeans for automatically continuously' taking up the slack of thesandpaper and keeping it under continuous proper tension around the drumWhlle the machine is in motion.

It is im ortant that the sand-paper on the drum sha1v be kept tightr andsmooth. If there is any slack, such,,for example, as is caused by theexpansion-due to dampness, it.

will puckerfand Wrinkle 'and then tear; or, if held rigidly tight, itwill also tear under contraction-due to dryness.

My y invention contemplates a gripping pressure under constant yieldingtension, which will'compensate for all expansion and contractionof thepaper, and hold it properly tight at all times and under all conditions,on the drum.

To this end my invention consists in the automatic .dripping andtensioning device, which I sha now fully describe by reference to theaccompanying drawings in which Figure l is a plan of the sand-paper drumof the machine, showing the gripper rolls turned to a position toinitially recrve the sand-paper between them. Fig. 2 is a longitudinalsection of the drum. Fig. 3 is a cross section of thedrum, the oripperrolls being turned to aposition for c amping the sand-paper andholdingit under tension. Fig. 4 is an elevation of one end of the drum.-Fig. 5 is an elevation of the other end of the .'lhe drum of thesand-papering machine comprises a'c'entral shaft 1, u on which aresecured the s iders 2 in an suitable number, and an encirc ing shell 3oiysteel or other ma- Specication of Lettera Patent. Application edAugust 29,1%7. Serial N o. 390,586.

residing in the tions,

Patented June 2, 1908.

terial, said shell heingnpenat/the top, as shown at 4.A f

Mounted rotatably per-rolls 5, which are ex osed through tie topopeningl of the shel and extend the whole len th of the drum. At one endthe gripper-ro ls are provided withjintermeshing gears 16,. (Fig. 5), tocause them t rotate in unison,1 and, at the other end', one ofsaidvrolls is squared, as seen at 7 in Fig. 1, to receive asocket-Wrench, toturn them, At one portion of its circumference, each gripperroll 1sflattened, as seen at 8 in Figs. 3 and 4, whereby when the rolls areturned up, these flat portions form, as shown inF'ig. 1, an entranceslot 8 to initially receive the sandpaper. The l slot formed bysaid`flat -porreferabiy, does not entend` quite to the en( s of the rolls,thereby forming an accurate guide for the entrance of the aper.

The holes in the spiderspokes in W 'ch one of the gri per-rolls ismounted are made slightly ob ong as seen in Figs, 3 and 4, in order topermit said yrolls to separate or .spread when the sand paper is clampedbetween thexn. A fiat spring 9 on each spider presses against the sideof that gripper-roll which is mounted in the oblong holes, and 4normallyholds it, relatively'to the other roll, with clamping force on thesand-pa er when the latter is between the rolls; ut when no sand-paperis between them, the pressure of the spring Q is limited by a lug 10against which the spring bears, thereby maintaining the proper width ofthe entrance slot 8 to receive the paper.

A .lug 11 is secured -near each end of the.

gri per-rolls, and'to each lug is ivoted a col ar-pin 12, thus forming atogg e connection with the Arolls. The othervend ofthe collar-pin 12passes freely down through a lug 13 von the spider. Spiral springs 14are seated on the pins between their collars and the lugs 13, and ,serveto normally continuously impose a pressure on the gripper-rolls tendingcontinuously to turn their tops towards each other.

15 is a pin fixed in the spiders to limitjghe turning o thegripper-rolls to a position to receive the. sand-paper.

in one spoke of each I spider are thegtwo adjacent and parallel gri ioolli- The operation of drum `is as follows With a 'socket wrench thegripper-rolls are turned until the lugs 11 rest against the pins 15,where they will stay at rest, by reason of the spring connection beingthrown past center. This position brings the ilat sides 8 of the rollsto the top and opposite each other to form the entrance slot S', shownin Fig. 1. The sand-paper being now wrapped upon the drum, its two endsare passed through the slot 8. Then the gripper-rolls are turned back,and their round sides now @rip the sand-paper, the springs 9 giving thec amping pressure. The lugs 1l and the collar-pins 12, with the springs14, being thus thrown to the other side oi the center, said springs nownot only hold the rolls in position, but also exert a constant tensionon the sand-paper to continuously keep it tight by compensating for itsexpansion or contraction. By this construction also, the tension isincreased by the centrifugal force due to the weight of the springs andtheir connections when the drum is rapidly revolving, and these partshave no tendency to throw the drum out of balance.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is 1. In combination with the drum of a sand-ypapering machine, a pair of gripper-rolls rotatably mounted in the drumand adapted to receive and clam the ends of the paper between them; anmeans acting on said rolls for imposing constant yielding rotativepressure to compensate for the expansion and contraction of the paperand to keep it under constant tension.

2. In combinationwith thedrum of a sandpapering machine, a pair ofgripper-rolls rotatably mounted in the drum and adapted to receive andclamp the ends of the paper between them; and springs connected withsaid rolls for imposing upon them constant yielding rotative pressure tocompensate for the eX ansion and contraction of the paper and to ecp itunder constant tension.

3. in combination wi th the drum of a sandpapering machine, a pair ofgripper-rolls rotatably mounted in the drum and adapted to receive andclamp the ends of the paper between them, said rolls having projectinglugs collar-pins pivotcd to said lugs; lugs in the drum through whichthe other ends of the collar-pins play; and springs on thecollarpins'disposed to impose on the rolls a constant yielding rotativepressure, to compensate l'or the expansion and contraction oi the paperand to keep it under constant tension.

4. ln combination with the drum of a sand-paperingr machine, a pair ofgripperrolls rotatably mounted in the drum and adapted to receive andclamp the ends ol' the paper between them, said ro ls havingr at oneportion ol their circumference correspondingly disposed flat sides, toform an entrance slot for the ends of the paper; and springs connectedwith said rolls for imposing upon them constant yielding rotativepressure, to

compensate for the expansion and contraction of the paper and to keep itunder constant tension.

5. In combination with the drum of a sand-papering machine, a pair ofgripperrolls rotatably mounted in the drum and adapted to receive andclam the ends of the paper between them, said ro ls having at one ortionof their circumference correspondingly disposed flat sides, to form anentrance slot for the ends of lthe paper; means for effecting therotation of the rolls in unison, to initially receive and clamp thepaper; and springs connected with lsaid rolls for imposing upon themconstant yielding rotative pressure, to compensate for the expansion andcontraction o the paper and to keep it under constant tension.

6. in combination with'the'drum ol. a sand-papering machine, a pair ofgripperrolls rotatably mounted in the drum and adapted to receive theends of the paper between them, one oi' said rolls being movable in itsbearings to and from the other; springs bearing on the movable roll toimpose a clamping pressure upon the paper; and means acting on saidrolls for imposing constant yielding rotative pressure to com ensate forthe expansion and contraction o vthe paper and to keep it under constanttension.

7 In combination with the drum of a sand-papering machine, a pair ofgripperrolls rotatably mounted in the drum and adapted to receive theends of the paper' between them, said rolls having at one portion oftheir circumference correspondingly disposed l'lat sides, to l'orm anentrance slot for the ends of the paper, and one o1c said rolls beingmovable in its bearinffs to and from the other; springs bearing on themovable roll to impose a clamping pressure on the paper; 'fixed stopsfor said springs to limit their pressure on said roll and means actingon said rolls for imposing constant yielding rotative pressure tocompensate for the expansion and contraction of t 1e paper and to keepit under constant tension.

8. In combination with the drum of a sand-papering machine, a pair ofgri per-rolls rotatably mounted in the drum am adapted to receive andclamp the ends of the paper between them, said rolls having at oneportieri of their circumference correspondingly disposed llat sides, toform an entrance slot for the ends of the aper; lugs on the rolls;collar-pins pivoter to said lues; lugs in the drum through which theother ends of the collar-pins play springs on the collar-pins disposedto impose on the rolls a constant yicding rotative pressure tocompensate for Sidonie in 'ntact-to' limit :the rotation A.of theWitnesses:

the ex ansion and. commotion of. the. paper In testimonyA whereof I havesigned my and to eep'ii; underconstaht tension means 'for4 turning the`rolls in unison-youd xed -pins in the drumogainst which the lgsoft/horolls l tw'osubscribing witnesses. f

rolls a'nd hold them in position to receive the name to this-speeicatiothe presence of

